Plastic air vent block



FIG. 1 is a top side perspective view of a plastic air vent block,showing my new design;

FIG. 2 is a bottom side perspective view thereof;

FIG. 3 is a side elevational view thereof;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a bottom plan view thereof.

The ornamental design for a plastic air vent block, as shown anddescribed.